©lANDRIA. MOI^OGTNIA. 19 



The Lemnas are minute aquatic plants, of an extremely 

 simpl;; structure, composed, at most, of 3 or 4 lenticular 

 leaves, laterally adnaie and proliferous, rarely fiovering. 

 Each leaf as a perfect plant, in aggregation, produces a 

 single floating radicle, or, in some species, a small bun- 

 dle of fibres. 



Species. 1. minor. 2. o-ibba. 3. thermalis, of Beauvois. 

 4? triiulca. (The genus of this plant is doubtful.) 



Obs Like many other aquatic plants the Lemnas are 

 common to almost every country and cliraate; they eve« 

 vegetate in the warniest thermsd springs. 



